The Non-Superneutrality of Money and its Distributional Effects when Agents are Heterogeneous and Capital Markets are Imperfect

In this paper we develop an OLG model with heterogeneous agents, money and bequests, introducing occupational choice and financing constraints when capital markets are imperfect. We show how, under appropriate conditions, all the moments of the distribution are affected by changes in money growth. More precisely, if capital markets are imperfect and heterogeneous agents are liquidity constrained, investment in fixed capital is not efficient and aggregate wages and profits depend on the availability of loanable funds. An increase in money growth may imply a more efficient aggregate investment. Therefore aggregate product and wealth positively depend on an acceleration in money growth.

Heterogeneity and Aggregation in a Financial Accelerator Model

In this paper we present a macroeconomic model in which changes in the variance (and higher moments of the distribution) of firm's financial conditions - i.e. "distributive shocks" - are bound to play a crucial role in the determination of output fluctuations. Firms differ by degree of financial robustness, which affects (optimal) investment in a bankruptcy risk context (à la Greenwald-Stiglitz). As to households, for the sake of simplicity, we assume that they are homogeneous in every respect so that we can adopt the representative agent hypothesis. We can explore the properties of the macro-dynamic model either via the study of the two-dimensional map defining the laws of motion of the average equity ratio and of the variance of the distribution or via simulations in a multiagent framework.

Was Bernanke Right? Targeting Asset Prices may not be a Good Idea after all

Should the central bank prevent “excessive” asset price dynamics or should it wait until the boom spontaneously turns into a crash and intervene only afterwards? The debate over this issue goes back at least to the exchange between Bernanke-Gertler (BG) and Cecchetti but has not settled yet. In their 1999 paper BG claimed that price stability and financial stability are ‘highly complementary and mutually consistent objectives’ in a flexible inflation targeting regime which ‘dictates that central banks ... should not respond to changes in asset prices, except insofar as they signal changes in expected inflation.’ (BG, 1999, p.18). This conclusion is straightforward within the variant of the NK-DSGE framework used by BG in which asset inflation shows up as a factor ‘augmenting’ the IS curve. In the present paper, we pursue a different modelling strategy so that, in the end, asset price dynamics will be incorporated into the NK Phillips curve. In our context it is not true anymore that by focusing on inflation the central bank is also checking an asset price boom. We put ourselves, therefore, in the best position to obtain a significant stabilizing role for asset price targeting. It turns out, however, that inflation volatility is higher in the asset price targeting case. After all, therefore, targeting asset prices may not be a good idea.cost channel, asset prices, Taylor rules

A look at the relationship between industrial dynamics and aggregate fluctuations

The firmly established evidence of right-skewness of the firms’ size distribution is generally modelled recurring to some variant of the Gibrat’s Law of Proportional Effects. In spite of its empirical success, this approach has been harshly criticized on a theoretical ground due to its lack of economic contents and its unpleasant long-run implications. In this chapter we show that a right-skewed firms’ size distribution, with its upper tail scaling down as a power law, arises naturally from a simple choice-theoretic model based on financial market imperfections and a wage setting relationship. Our results rest on a multi-agent generalization of the prey-predator model, firstly introduced into economics by Richard Goodwin forty years ago.Firm size; Prey-predator model; Business Fluctuations

Asset Prices and Monetary Policy: A New View of the Cost Channel

Should the central bank act to prevent "excessive" asset price dynamics or should it wait until the boom spontaneously turns into a crash and intervene afterwards to attenuate the fallout on the real economy? The standard "three equation" New Keynesian framework is inadequate to analyse this issue for the very simple reason that asset prices are not explicitly included in the model. There are two straightforward ways to take into account asset price dynamics in this framework. First of all, the objective function of the central bank - usually defined in terms of inflation and the output gap - could be "augmented" to take into account asset price inflation. Second, expected asset price inflation can affect the IS curve through a wealth effect. In this paper we follow a different route. In our model in fact, the expected asset price dynamics will be eventually incorporated into the NK Phillips curve. This is due to the assumption of a cost channel for monetary policy which is activated whenever monetary policy affects asset prices and dividends. In fact they determine the cost of external finance in the simple "equity only" financing model we consider, abstracting for simplicity from internal funds and the credit market.

Credit Cycles in a OLG Economy with Money and Bequest

In this paper we develop an extended version of the original Kiyotaki and Moore's model ("Credit Cycles" Journal of Political Economy, vol. 105, no 2, April 1997)(hereafter KM) using an overlapping generation structure instead of the assumption of infinitely lived agents adopted by the authors. In each period the population consists of two classes of heterogeneous interacting agents, in particular: a financially constrained young agent (young farmer), a financially constrained old agent (old farmer), an unconstrained young agent (young gatherer), an unconstrained old agent (old gatherer). By assumption each young agent is endowed with one unit of labour. Heterogeneity is introduced in the model by assuming that each class of agents use different technologies to pro- duce the same non durable good. If we study the effect of a technological shock it is possible to demonstrate that its effects are persistent over time in fact the mechanism that it induces is the reallocation the durable asset ("land")among agents. As in KM we develop a dynamic model in which the durable asset is not only an input for production processes but also collateralizable wealth to secure lenders from the risk of borrowers'default. In a context of intergenerational altruism, old agents leave a bequest to their offspring. Money is a means of payment and a reserve of value because it enables to access consumption in old age. For simplicity we assume that preferences are defined over consumption and bequest of the agent when old. Money plays two different and contrasting roles with respect to landholding. On the one hand, given the bequest, the higher the amount of money the young wants to hold, the lower landholding. On the other hand the higher the money of the old, the higher the resources available to him and the higher bequest and landholding. We study the complex dynamics of the allocation of land to farmers and gatherers - which determines aggregate output - and of the price of the durable asset. If a policy move does not change the ratio of money of the farmer and of the gatherer, i.e. if the central bank changes the rates of growth of the two monetary aggregates by the same amount, monetary policy is superneutral, i.e. the allocation of land to the farmer and to the gatherer does not change, real variables are unaffected and the only e¤ect of the policy move is an increase in the rate of inflation, which is pinned down to the (uniform) rate of change of money, and of the nominal interest rate. If, on the other hand, the move is differentiated, i.e. the central bank changes the rates of growth of the two monetary aggregates by different amounts so that the rates of growth are heterogeneous, money is not superneutral, i.e. the allocation of land changes and real variables are permanently affected, even if the rates of growth of the two aggregates go back to the original value afterwardsCredit Cycles, monetary policy

Adaptive microfoundations for emergent macroeconomics

In this paper we present the basics of a research program aimed at providing microfoundations to macroeconomic theory on the basis of computational agentbased adaptive descriptions of individual behavior. To exemplify our proposal, a simple prototype model of decentralized multi-market transactions is offered. We show that a very simple agent-based computational laboratory can challenge more structured dynamic stochastic general equilibrium models in mimicking comovements over the business cycle.Microfoundations of macroeconomics, Agent-based economics, Adaptive behavior

"Credit Cycle" in an OLG Economy with Money and Bequest

In the late '90s Kiyotaki and Moore (KM) put forward a new framework (Kiyotaki and Moore,1997) to explore the Financial Accelerator hypothesis. The original model was framed in an Infinitely Lived Agent context (ILA-KM economy). As in KM we develop a dynamic model in which the durable asset ("land") is not only an input but also collateralizable wealth to secure lenders from the risk of borrowers' default. In this paper, however, we model an OLG-KM economy whose novel feature is the role of money as a store of value and of bequest as a vehicle of resources to be "invested" in landholding. The dynamics generated by the model are complex. Not only cyclical patterns are routinely generated but the periodicity and amplitude are irregular. A route to chaotic dynamics is open.